Destaticized phonograph records and method for producing same



Patented June 1, 1954 DESTATICIZED PHONOGRAPH RECORDS AND METHOD FOR PRODUCING SAME John B. Eisen, Waterloo, Wis., assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application October 18, 1949, Serial No. 122,135

12 Claims. 1

This invention relates to phonograph records and to methods for eliminating the highly undesirable effects of electrostatic charges which build up on such phonograph records, more particularly phonograph records of the. type comprising polyvinyl chloride, polystyrene or copolymers of either.

Phonograph records made of such polymers have been particularly subject to the objectionable characteristics resulting from high electrostatic susceptibility. As a result of such susceptibility, these records accumulate high electrostatic charges which attract dust, lint, tobacco ashes, and like materials and cause such particles to cling tenaciously to the records. During the playing of such a record these materials clog the needle, produce undue record wear and objectionable surface noises and deleteriously afiect the tone. An undesirable clicking noise is also produced which is thought to be directly due to discharge of the electrostatic charge to the phonograph pick-up arm.

Prior to this time, no method for eliminating these defects has been described which will remain effective over an indefinite period of time, or which constitutes more than an essentially temporary treatment, or which is independent of the ambient humidity. The methods of the prior art depend on the property of directly wetting the record with an aqueous material or upon the property of deliquescence to cause the record to be so wetted. Such materials include glycols, glycerine, sorbitol, sulfonates, and the materials disclosed in U. S. Patent 2,403,960. These treatments produce only a temporary absence of electrostatic charge; the length of time during which the treatment remains eiiective being dependent on the ambient humidity. In dry climates the duration is very short. The efiectiveness of such treatments may be renewed by wiping the record with a wet cloth or otherwise wetting it but such re-treatment remains effective only until the water dries. A record which has been treated by such a method, and then allowed to remain in an album or envelope until dry acquires an electrostatic charge from friction with the paper upon merely being removed from such a container.

My invention, on the other hand, provides substantially relatively permanent freedom from the disadvantages of electrostatic charges on such records. This invention does not in any way depend on wetting the record with aqueous or. deliquescent substances and therefore produces results substantially independent of humidity. :Afurther advantage of my invention overthe prior artis that it makes possible the production of electrostatically non-susceptible records directly by the manufacturer, instead of being restricted to a method of treatment suitable only for the retailer or ultimate customer.

An object of this invention is therefore to provide a method for eliminating the effects of electrostatic charges on phonograph records.

Another object is to provide phonograph records comprising polymers, e. g., polyvinyl chloride or polystyrene, which are free of the effects of electrostatic charges.

Another object is to provide a method of making phonograph records substantially permanently free from the effects of electrostatic charges.

Further objects and advantages of this invention will become apparent from the etailed description.

In accordance with this invention, I applya selected substance to a phonographrecord made of a resin comprising polyvinyl chloride, polystyrene, or copolymers of either, for example, a record comprising the polyvinyl chloride-containing resin Vinylite. The substance applied is selected from the group consisting of aliphatic amines, aliphatic quaternary ammonium salts and aliphatic amine salts which contain at least one aliphatic radical having at least8 carbon atoms, and dialkylsodium-sulfosuccinates which have at most 12 carbon atoms in each alkyl radical, according to their'suitability as pointed out below.

Application of the substance may be accomplished by wiping the record with a cloth' containing the substance or a solution containing it or with other sorts of wiping or applicator devices such as brushes, felt pads, and the like, or it may be accomplished by coating the mold in which the record is madeor by incorporating the compound in the material from which the record is made.

The applicability of the invention will become further apparent from the following specific examples which are given here by way of illustration only, and not in any sense of limitation whatever. The parts shown in the examples are by Weight.

Example I A microgroove phonograph record of the type known commercially as long-playing, made of a material comprisingpolyvinyl chloride and having a diameter of 12 inches and carrying. a considerable electrostatic charge as evidenced by-attraction for dust and cigarette ashes and byclicking noises occurring during playing was thoroughly wetted with the following solution:

1 part dialkyldimethyl ammonium chloride of the grade sold commercially as Arquad 2-0 99 parts water by wiping the record with a cotton cloth dipped in the solution.

Arquad 2-0 is a commercially available tetraalkyl quaternary ammonium salt in whichtwo of the alkyl groups are derived from a mixture of alcohols containing 8% octyl, alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and 10% octadecyl alcohol.

After minutes the record was wiped dry'with a dry cotton cloth. The susceptibility of the rec- 0rd to becoming electrostatically charged was im- Example II A microgroove phonograph record of the type known commercially as 45 R. P. M., made of a material comprising polyvinyl chloride and having a diameter of 7 inches, and carrying a considerable electrostatic charge as evidenced by attraction for dust and cigarette ashes and by clicking noises occurring during playing was thoroughly wetted with the folowing solution:

1 part diethylcyclohexylamine salt of lauryl sulfate of the grade sold commercially as Duponol G 999 parts water by wiping the record with a cotton cloth dipped in the solution. After 5 minutes the record was wiped dry with a dry cotton cloth. The susceptibility of the record to becoming electrostatically charged was immediately determined by rubbing it vigorously with a wool cloth and then observing the amount of attractive force exerted on lint and cigarette ashes and the presence of a clicking noise during playing. No effects whatever of the presence of an electrostatic charge on the record could be observed. The record was placed in an envelope and was thereafter withdrawn, played, and returned to the envelope once each day. At the end of one year there were still no observable eifects of the presence of an electrostatic charge.

Example III A microgroove phonograph record of the type known commercially as long-playing, made of a material comprising polyvinyl chloride and having a diameter of 12 inches, and carrying a considerable electrostatic charge as evidenced by attraction for dust and cigarette ashes and by clicking noises occurring during playing was thoroughly wetted with the following solution:

2 parts dialkyldimethyl ammonium chloride of the grade sold commercially as Arquad 2-0 19 parts water 19 parts isopropanol by wiping the record with a cotton cloth dipped in the solution. After 10 minutes the record was wiped dry with a dry cotton cloth. The susceptibility of the record to becoming electrostatically charged was immediately determined by rubbing it vigorously with a wool cloth and then observing the amount of attractive force exerted on lint and cigarette ashes and the presence of a clicking noise during playing. No effects whatever of the presence of an electrostatic charge on the record could be observed. The record was placed in an envelope and was thereafter withdrawn, played, and returned to the envelope once each day. At the end of one year there were still no observable efiects of the presence of an electrostatic charge.

Escample IV A phonograph record of the type known commercially as childrens records, made of a material comprising polystyrene and having a diameter of 6 inches, and carrying a considerable electrostatic charge as evidenced by attraction for dust and cigarette ashes and by clicking noises occurring during playing was thoroughly wetted with the following solution:

1 part alkylamine acetate of the grade sold commercially as Armac CD 1 part diethylcyclohexylamine salt of lauryl sulfate of the grade sold commercially as Duponol G 198 parts isopropanol by wiping the record with a cotton cloth dipped in th solution.

Armac CD is an alkyl amine acetate derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and 10 octadecyl alcohol.

After 5 minutes the record was wiped dry with a cotton cloth. The susceptibility of the record to becoming electrostatically charged was immediately determined by rubbing it vigorously with a wool cloth and then observing the amount of attractive force exerted on lint and cigarette ashes and the presence of a clicking noise during playing. No effects whatever of the presence of an electrostatic charge on the record could be observed. The record was placed in an envelope and was thereafter withdrawn, played, and returned to the envelope once each day. At the end of one year there were still no observable eifects of the presence of an electrostatic charge.

Example V A microgroove phonograph record of the type known commercially as long-playing, made of a material comprising a copolymer of vinyl chloride and vinyl acetate and having a diameter of 12 inches, and carrying a considerable electrostatic charge as evidenced by attraction for dust and cigarette ashes and by clicking noises occurring during playing was thoroughly wetted with the following solution:

3 parts l2-hydroxy stearic acid 2 parts monoalkylamine of the grade sold oommercially as Armeen CD 495 parts isopropanol by wiping the record with a cotton cloth dipped in the solution.

Armeen CD is a monoalkyl amine in which the alkyl group is derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and 10% octadecyl alcohol.

After 30 seconds the record was wiped dry with a dry cotton cloth. The susceptibility of the record to becoming electrostatically charged was immediately determined by rubbing it vigorously with a wool cloth and then observing the amount of attractive force exerted on lint and cigarette ashes and the presence of a clicking noise during playing. No effects whatever of the presence of an electrostatic charge on the record could be observed. The record was placed in an envelope and was thereafter withdrawn, played, and returned to the envelope once each day. At the end of one year there were still no observable effects of the presence of an electrostatic charge.

Example VI A microgroove phonograph record of the type known commercially as long-playing, made of a material comprising polyvinyl chloride and having a diameter of 12 inches, and carrying a considerable electrostatic charge as evidenced by attraction for dust and cigarette ashes and by clicking noises occurring during playing was thoroughly wetted with the following solution:

1 part dioctylsodiumsulfosuccinate of the grade sold commercially as Deceresol OT 199 parts isopropanol by wiping the record with a cotton cloth dipped in the solution. After 5 minutes the record was wiped dry with a dry cotton cloth. The susceptibility of the record to becoming electrostatically charged was immediately determined by rubbing it vigorously with a wool cloth and then observing the amount of attractive force exerted on lint and cigarette ashes and the presence of a clicking noise during playing. No effects whatever of the presence of an electrostatic charge on the record could be observed. The record was placed in an envelope and was thereafter withdrawn, played, and returned to the envelope once each At the end of one year there were still no observable effects of the presence of an electrostatic charge.

The above examples indicate the breadth of the applicability of my invention but by no means do they exhaust the different possible applicaticns.

While reference has been made to the use of a cotton cloth for applying the solution to the phonograph records, it should be clearly understood that this is not at all to be considered restrictive and that the invention relates to any sort of means known to the prior art for ensuring the presence of molecules of a material at surface of a solid object made of some other substance. Such means may include incorporaticn of the material in a formulation from which the solid object is subsequently made.

The examples have shown theuse of several materials as suitable for use in eliminating the effects of electrostatic charges on synthetic resin phonograph records. These are not to be considered limiting in any respect, the invention being in no way confined to these particular materials. Substances which are most suitable for the purpose of this invention are those salts of alkylamines in which the compound attached to the amine to form the salt has an alkyl radical containing at least 8 carbon atoms, those quaternary alkyl ammonium salts which have at least one alkyl radical containing at least 8 carbon atoms and those dialkylsodiumsulfosuccinates which have at most 12 carbon atoms in each alkyl radical. Also suitable to some degree are those tertiary alkylamines which contain at least one alkyl radical having at least 8 carbon atoms and the salts of such amines wherein the compound attached to the amine to form the salt contains 1 to"? carbon atoms. The corresponding primary alkylamines and alkylamine salts are also suitable but to a lesser degree. Among these compounds are, for example, stearyldimethylamine, lauryldiethylamine acetate, and stearyldipropyl ammonium chloride. The salts include, for example only, those formed with halogen acids, acetic acid, sulfuric acid and phosphoric acid.

While I do not wish to commit myself to any particular theory as to the mode of functioning of this invention, it is my belief that electrostatic charge which exists on the resin, in the absence of anti-electrostatic material, consists of a cloud of electrons, these electrons having been acquired from friction with materials such as steel, glass, sapphire, paper and cloth which have more or less easily-detachable electrons. In the presence of anti-electrostatic material, the charge is dissipated by sorption of the electrons into the material. It is thought that the electrons enter the molecules of the material, consequently changing energy levels within the molecules and causing readjustment of the orientation of these molecules. By reason of the surface anchorage of these molecules, it is possible that those parts of the molecules which are more remote from the anchored ends may be in a state of electro-isomeric equilibrium with the plastic surface. In this manner, electrons may be consumed by the energy requirements of sorption into the molecules or by the alternative states of orientation and disorientation of the molecules.

It is also strongly believed that anti-electrostatic activity is not due to conductivity of the anti-electrostatic material; for example, diethylcyclohexylamine salt of lauryl sulfate of the grade sold commercially as Duponol G has a very high dielectric constant and some of the best anti-electrostatic agents have an electrical resistance equal to that of transformer oil.

The foregoing examples show the use of water, isopropanol and a mixture of the two as solvents for use in treating phonograph records according to my invention but this is in no way to be restrictively construed. Any liquid is suitable as a solvent for the purposes of this invention which is miscible with the particular material to be used in the treatment but which does not dissolve, plasticize or soften the material of which the record is made and does not soften the surface or weaken the internal structure near the surface of the material of the record. Thus, ketones and many hydrocarbons are not suitable for use with records comprising polyvinyl chloride, whereas low-molecular-weight alcohols such as isopropanol and ethanol dissolve most of the materials which are satisfactory as anti-electrostatic agents for this invention but do not affect such records adversely.

The examples have shown solutions having concentrations of 0.1 to 5.0 percent anti-electrostatic agent as being suitable for my invention. This is not limiting, best results being obtained in the range 0.05 to 5.0 percent, which I prefer. Useful results, however, are obtained with concentrations of 0.005 to 100.00 percent, the principal dis- 7 advantages, insofar as they exist, being that below 0.05 percent the duration of the results of the treatment may be less than one year and above 5.0 percent, material is wasted.

The examples have shown the application of my invention to phonograph records comprising polyvinyl chloride and to records comprising polystyrene but this is not limiting. It may also be applied to phonograph records comprising any synthetic resin known to the prior art as being capable of acquiring an electrostatic charge, such as, for example, cellulose acetate, cellulose acetate-butyrate, polymethylmethaerylate, polyamides, polyethylene, polyfluoroethylene, polyacrylonitrile, halogenated polystyrenes, polydivinylbenzenes, polystilbenes, polybutenes and rubber.

The invention is seen as covering broadly the idea of applying a material to synthetic resin phonograph records to produce substantially permanent elimination of the efiects of electrostatic charges on such records, such material being selected from one of these three groups: aliphatic amines, aliphatic quaternary ammonium salts and aliphatic amine salts, which contain at least one aliphatic radical having at least 12 carbon atoms in each alkyl radical, according to their suitability as pointed out above.

It is thus apparent that the invention is broad in scope, and is not to be restricted except by the claims, in which it is my intention to cover all novelties inherent in the invention as broadly as possible, in view of prior art.

I claim:

1. A method of treating phonograph records comprising a resinous base material which comprises thoroughly wetting the surface of said base material with a solvent solution of a destaticizing substance selected from the group consisting of monoalkyl amines and dialkyl dimethyl ammonium chlorides wherein the allcyl groups are derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 4 7% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and 10% octadecyl alcohol, and thereafter drying said surface, said solvent solution containing from 0.5 to 5.0%, by weight, of said destaticizing substance.

2. A method of treating phonograph records as in claim 1 wherein the resinous base material is polyvinyl chloride.

3. A method of treating phonograph records as in claim 1 wherein the resinous base material is polystyrene.

1. A method of treating phonograph records as in claim 1 wherein the resinous base material is a copolymer of vinyl chloride and vinyl acetate.

5. A method of treating phonograph records comprising polystyrene which comprises thoroughly wetting the surface of said record with a solvent solution of a monoalkyl amine in which the alkyl group is derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and 10% octadecyl alcohol, and thereafter drying said surface, said 8 solvent solution containing from 0.5 to 5.0%, by Weight, of said monoalkyl amine.

6. A method of treating phonograph records comprising polystyrene which comprises thoroughly wetting the surface thereof with a solvent solution of a dialkyl dimethyl ammonium chloride in which the dialkyl groups are derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 9% hexadecyl alcohol, and 10% octadecyl alcohol, and thereafter drying said surface, said solvent solution containing from 0.5 to 5.0% by weight, of said dialkyl dimethyl ammonium chloride.

7. An article of manufacture comprising a phonograph record comprising a resinous base material the surface of said record carrying a coating thereon consisting of a substance selected from the group consisting of monoalkyl amines and dialkyl dimethyl ammonium chlorides, the alkyl groups of which are derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and 10% octadecyl alcohol.

8. An article of manufacture as in claim 7 wherein the resinous base material comprises polyvinyl chloride.

9. An article of manufacture as in claim 7 wherein the resinous base material comprises polystyrene.

10. An article of manufacture as in claim '7 wherein the resinous base material comprises a copolymer of vinyl chloride and vinyl acetate.

11. An article of manufacture comprising a phonograph record comprising polystyrene, the surface of said record carrying a coating thereon consisting of a monoalkyl amine in which the alkyl group is derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and. 10% octadecyl alcohol.

12. An article of manufacture comprising a phonograph record comprising polystyrene, the surface of said record carrying a coating thereon consistin of a dialkyl dimethyl ammonium chloride in which the alkyl groups are derived from a mixture of alcohols containing 8% octyl alcohol, 9% decyl alcohol, 47% dodecyl alcohol, 18% tetradecyl alcohol, 8% hexadecyl alcohol and 10% octadecyl alcohol.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,197,930 Jackson et al Apr. 23, 1940 2,381,020 Wilkes et a1. Aug. 7, 1945 2,393,863 Myers Jan. 29, 1946 2,403,960 Stoops et al July 16, 1946 2,463,282 Kang Mar. 1, 1949 2,581,836 Cresswell Jan. 8, 1952 FOREIGN PATENTS Number Country Date 484,434 Great Britain May 5. 1938 

1. A METHOD OF TREATING PHONOGRAPH RECORDS COMPRISING A RESINOUS BASE MATERIAL WHICH COMPRISES THOROUGHLY WETTING THE SURFACE OF SAID BASE MATERIAL WITH A SOLVENT SOLUTION OF A DESTATICIZING SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF MONOALKYL AMINES AND DIALKYL DIMETHYL AMMONIUM CHLORIDES WHEREIN THE ALKYL GROUPS ARE DERIVED FROM A MIXTURE OF ALCOHOLS CONTAINING 8% OCTYL ALCOHOL, 9% DECYL ALCOHOL 47% DODECYL ALCOHOL, 18% TETRADECYL ALCOHOL, 8% HEXADECYL ALCOHOL AND 10% OCTADECYL ALCOHOL, AND THEREAFTER DRYING SAID SURFACE, SAID SOLVENT SOLUTION CONTAINING FROM 0.5 TO 5.0%, BY WEIGHT, OF SAID DESTATICIZING SUBSTANCE. 